on 03-Sep-2020 (Thu)

In 1910, a bold solution was put forth by the New Foods Society. Their plan was to import and release hippopotamus from Africa into the rivers and bayous of Louisiana. The hippopotamus would then eat the water hyacinth and also produce meat to solve another serious problem at the time, the American meat crisis.^[32]

Known as the American Hippo bill, H.R. 23621 was introduced by Louisiana Congressman Robert Broussard and debated by the Agricultural Committee of the U.S. House of Representatives. The chief collaborators in the New Foods Society and proponents of Broussard's bill were Major Frederick Russell Burnham, the celebrated American Scout, and Captain Fritz Duquesne, a South African Scout who later became a notorious spy for Germany. Presenting before the Agricultural Committee, Burnham made the point that none of the animals that Americans ate, chickens, pigs, cows, sheep, lambs, were native to the U.S.; all had been imported by European settlers centuries before, so why should Americans hesitate to introduce hippopotamus and other large animals into the American diet? Duquesne, who was born and raised in South Africa, further noted that European settlers on that continent commonly included hippopotamus, ostrich, antelope, and other African wildlife in their diets and suffered no ill effects. The American Hippo bill nearly passed, but fell one vote short.^[32]

As the hyanciths multiply into mats, they eliminate the presence of fish, and choke waterways for boating and shipping.^[47] This effect was well taking hold in the state of Louisiana by the turn of the 20th century.^[32]

The plant invaded Florida in 1890,^[48] and an estimated 50 kg/m² of the plant mass choked Florida's waterways

Thus in the early 20th century, the U.S. War Department (i.e., the Army Corps of Engineers) tested various means of eradicating the plants, including the jet-streaming of steam and hot water, application of various strong acids, and application of petroleum followed by incineration.^[f] Spraying with saturated salt solution (but not dilute solutions) effectively killed the plants; unfortunately this was considered prohibitively expensive, and the engineers selected Harvesta brand herbicide, whose active ingredient was arsenic acid, as the optimal cost-effective tool for eradication.^[52][53] This herbicide was used until 1905, when it was substituted with a different, white arsenic based compound.^[53] An engineer charged with the spraying did not think the poison to be a matter of concern, stating that the crew of the spraying boat would routinely catch fish from their working areas and consume them.^[54] However, spraying had little hope of completely eradicating the water hyacinth, due to the vastness of escaped colonies and the inaccessibility of some of the infested areas, and the engineer suggested that some biological means of control may be needed. ^[55]

Groundwater recharge or deep drainage or deep percolation is a hydrologic process, where water moves downward from surface water to groundwater

Groundwater is the water present beneath Earth's surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock become completely saturated with water is called the water table

A seep puddle in a forest clearing

A sinkhole, also known as a cenote, sink, sink-hole,^[1][2] swallet, swallow hole, or doline (the different terms for sinkholes are often used interchangeably^[3]), is a depression or hole in the ground caused by some form of collapse of the surface layer. Most are caused by karst processes – the chemical dissolution of carbonate rocks^[4] or suffosion processes

An algal bloom or algae bloom is a rapid increase or accumulation in the population of algae in freshwater or marine water systems, and is often recognized by the discoloration in the water from their pigments.^[2] The term algae encompasses many types of aquatic photosynthetic organisms, both macroscopic, multicellular organisms like seaweed and microscopic, unicellular organisms like cyanobacteria.^[3] Algal bloom commonly refers to rapid growth of microscopic, unicellular algae, not macroscopic algae

The trophic level of an organism is the position it occupies in a food web. A food chain is a succession of organisms that eat other organisms and may, in turn, be eaten themselves. The trophic level of an organism is the number of steps it is from the start of the chain. A food web starts at trophic level 1 with primary producers such as plants, can move to herbivores at level 2, carnivores at level 3 or higher, and typically finish with apex predators at level 4 or 5

An apex predator, also known as an alpha predator or top predator, is a predator at the top of a food chain, without natural predators

Algal blooms are the result of a nutrient, like nitrogen or phosphorus from fertilizer runoff, entering the aquatic system and causing excessive growth of algae. An algal bloom affects the whole ecosystem. Consequences range from the benign feeding of higher trophic levels, to more harmful effects like blocking sunlight from reaching other organisms, causing a depletion of oxygen levels in the water, and, depending on the organism, secreting toxins into the water. The process of the oversupply of nutrients leading to algae growth and oxygen depletion is called eutrophication.

definitions of blooms have included when the concentration of chlorophyll exceeds 100 mg/L,^[5] when the concentration of chlorophyll exceeds 5 ug/L,^[6] when the species considered to be blooming exceeds concentrations of 1000 cells/mL,^[7] and when the algae species concentration simply deviates from its normal growth

Blooms are the result of a nutrient that the particular algae need being introduced to the local aquatic system. This growth-limiting nutrient is typically nitrogen or phosphorus, but can also be iron, vitamins, or amino acids.^[3] There are several mechanisms for the addition of these nutrients in water. In the open ocean and along coastlines, upwelling from both winds and topographical ocean floor features can draw nutrients to the photic, or sunlit zone of the ocean.^[10] Along coastal regions and in freshwater systems, agricultural, city, and sewage runoff can cause algal blooms

Diatoms (diá-tom-os 'cut in half', from diá, 'through' or 'apart'; and the root of tém-n-ō, 'I cut'.)^[10] are a major group of algae,^[11] specifically microalgae, found in the oceans, waterways and soils of the world. Living diatoms make up a significant portion of the Earth's biomass: they generate about 20 to 50 percent of the oxygen produced on the planet each year,^[12][13] take in over 6.7 billion metric tons of silicon each year from the waters in which they live,^[14] and constitute nearly half of the organic material found in the oceans. The shells of dead diatoms can reach as much as a half-mile (800 m) deep on the ocean floor, and the entire Amazon basin is fertilized annually by 27 million tons of diatom shell dust transported by transatlantic winds from the African Sahara, much of it from the Bodélé Depression, which was once made up of a system of fresh-water lakes.^[15][16]

Diatoms are unicellular: they occur either as solitary cells or in colonies, which can take the shape of ribbons, fans, zigzags, or stars. Individual cells range in size from 2 to 200 micrometers

In the presence of adequate nutrients and sunlight, an assemblage of living diatoms doubles approximately every 24 hours by asexual multiple fission; the maximum life span of individual cells is about six days.^[18] Diatoms have two distinct shapes: a few (centric diatoms) are radially symmetric, while most (pennate diatoms) are broadly bilaterally symmetric. A unique feature of diatom anatomy is that they are surrounded by a cell wall made of silica (hydrated silicon dioxide), called a frustule.^[19] These frustules have structural coloration due to their photonic nanostructure, prompting them to be described as "jewels of the sea" and "living opals

Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula SiO₂, most commonly found in nature as quartz and in various living organisms

Eyes [ edit ]

Macro photo of a scallop showing some of its bright blue eyes

Scallops have a large number (up to 200) of small (about 1 mm) eyes arranged along the edge of their mantles. These eyes represent a particular innovation among molluscs, relying on a concave, parabolic mirror of guanine crystals to focus and retro-reflect light instead of a lens as found in many other eye types.^[9] Additionally, their eyes possess a double-layered retina, the outer retina responding most strongly to light and the inner to abrupt darkness.^[10] While these eyes are unable to resolve shapes with high fidelity, the combined sensitivity of both retinas to light entering the eye and light retro-reflected from the mirror grants scallops exceptional contrast definition, as well as the ability to detect changing patterns of light and motion.^[11][12] Scallops primarily rely on their eyes as an 'early-warning' threat detection system, scanning around them for movement and shadows which could potentially indicate predators. Additionally, some scallops alter their swimming or feeding behavior based on the turbidity or clarity of the water, by detecting the movement of particulate matter in the water column

A pearl is a hard, glistening object produced within the soft tissue (specifically the mantle) of a living shelled mollusk or another animal, such as fossil conulariids. Just like the shell of a mollusk, a pearl is composed of calcium carbonate (mainly aragonite or a mixture of aragonite and calcite)^[3] in minute crystalline form, which has deposited in concentric layers. The ideal pearl is perfectly round and smooth, but many other shapes, known as baroque pearls, can occur

A harmful algal bloom (HAB) is an algal bloom that causes negative impacts to other organisms via production of natural toxins, mechanical damage to other organisms, or by other means. The diversity of these HABs make them even harder to manage, and present many issues, especially to threatened coastal areas.^[27] HABs are often associated with large-scale marine mortality events and have been associated with various types of shellfish poisonings

Nitrate is a polyatomic ion with the chemical formula NO ⁻
₃ . Salts containing this anion are called nitrates. Nitrates are common components of fertilizers and explosives.^[1] Almost all nitrates are soluble in water. A common example of an inorganic nitrate salt is potassium nitrate (saltpeter). Removal of one electron yields the nitrate radical, also called nitrogen trioxide NO
₃ .

Potassium nitrate is a chemical compound with the chemical formula KNO
₃ . It is an ionic salt of potassium ions K⁺ and nitrate ions NO₃⁻, and is therefore an alkali metal nitrate.

It occurs in nature as a mineral, niter. It is a source of nitrogen, and nitrogen was named after niter.

Major uses of potassium nitrate are in fertilizers, tree stump removal, rocket propellants and fireworks. It is one of the major constituents of gunpowder (black powder).^[6] In processed meats, potassium nitrate reacts with hemoglobin and generates a pink color.^[7]

Potassium nitrate is one of several nitrogen-containing compounds collectively referred to as saltpeter or saltpetre.

A rich source of inorganic nitrate in the human diets come from leafy green foods, such as spinach and arugula. NO ⁻
₃ (inorganic nitrate) is the viable active component within beetroot juice and other vegetables. Drinking water is also a dietary source.^[2]

Dietary nitrate supplementation delivers positive results when testing endurance exercise performance.^[3]

Phytoplankton ( / ˌ f aɪ t oʊ ˈ p l æ ŋ k t ə n / ) are the autotrophic (self-feeding) components of the plankton community and a key part of oceans, seas and freshwater basin ecosystems. The name comes from the Greek words φυτόν (phyton), meaning "plant", and πλαγκτός (planktos), meaning "wanderer" or "drifter".^[1] Most phytoplankton are too small to be individually seen with the unaided eye. However, when present in high enough numbers, some varieties may be noticeable as colored patches on the water surface due to the presence of chlorophyll within their cells and accessory pigments (such as phycobiliproteins or xanthophylls) in some species. About 1% of the global biomass is due to phytoplankton.^[2]

Phytoplankton are photosynthesizing microscopic biotic organisms that inhabit the upper sunlit layer of almost all oceans and bodies of fresh water on Earth. They are agents for primary production, the creation of organic compounds from carbon dioxide dissolved in the water, a process that sustains the aquatic food web

Phytoplankton are extremely diverse, varying from photosynthesising bacteria (cyanobacteria), to plant-like diatoms, to armour-plated coccolithophores.^[4]

cyanobacteria diatom dinoflagellate green algae coccolithophore Some phytoplankton types (not to scale)